Cutter for sewing machines



Aug. 1a, 1925. 1,550,418

A. M. BATES CUTTER FOR SEWING MACHINES Filed April 20, 1922 "p; PMLAPWPatented Aug. 18, 1925.

UNITED STATES 1,550,413 PATENT OFFICE.

ADELMER M. BATES, OF CHICAGO, ILLINOIS, ASSIGNOR '10 BATES VALVE BAGCOM- 'PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF WEST VIRGINIA.

CUTTER FOR SEWING LIACHINES.

. Application filed April 20, 1922. Serial No. 555,663.

To all whom it may concern:

Be it known that I, AnnLMER M. BATES, a citizen of the United States,residin at Chicago, in the county of Cook and tate of Illinois, haveinvented a certain new and useful Improvement in Cutters for SewingMachines, of which the following is a specification.

My invention relates to improvements in cutters for sewing machineswherein two needles operate to sew parallel seams and wherein the fabricor material being sewn is out between the seams. The device is primarilyused in connection with a bag form ing and filling machine in which atube or bag-forming fabric is fed out by successive sections and thetube is passed between the sewing machines so as to close the open endof a, filled bag and cut it off from the tube,

'20 and at the same time sew the seam which the operating means;

Figure 2 is a partial plan view showing the cutter in cutting positionand the needles down to form the stitch;

Figure 3 is a section along the line 3-3 of Fig. 1; Y

Figure 4 is a section "along the line4-4 of Fig. 3; L

Figure 5 is a detailed section on an enlarged scale showing the cutterat the end of its cutting stroke;

Figure 6 is a diagrammatic plan view showing the relation between theposition of the seam and the cutter. as the work is going on.' y

Figure 7 is a detailed view ofthe knives.

A is a supporting arm adapted to contain the stitch-forming mechanismand the workfeeding mechanism. It carries a throat plate A which coversthese various mechanisms, none of which are here shown as they form' nopart of my invention. A" is a presser foot in opposition to the throatplate, carried by a presser foot dles and cutter retracted, andillustrating bar A mounted for reciprocation in lugs A A. A is a needlebar also mounted for reciprocation in the In s A A and it carries theneedles A A adapted to reciprocate through perforations A A of thepresser foot, so as to make two par- 6 fallel seams, A A. All thismechanism is merely the'ordinary type of double needle or double seamsewing machine.

The rear extension of the presser foot is slotted as at B. B is a knifecarrying shaft mounted in suitable bearings B and operated, forexamplefthrough the lever B and the pivoted link 13. On the bottom of,the shaft is a bracket B whichextends forwardly therefrom in thedirection of the presser foot. It; has'adjustably mounted thereon aknife B slotted as at B to permit adjustment toward and from the work.The bracket has a flange B engaging the.

knife to hold it against lateral or angular displacement, and theadjusting screw 13 adapted to clamp the knife in place. The knife isreduced at its lower end as at, B and the end of the knife is inclinedas at B away from the cutting edge so as to get proper clearance.

- C is a fixedknifeblade having a cutting edge. It projects upwardlyfrom the throat plate, and is rearwardly inclined, as shown in Figure 7,so that the heels of the two I knives are never disengaged. While thereciprocating knife moves simultaneously with the needles, it passesthrough a shorter path, as will be seen by comparing Figs. 1 and 2. Theseparate short-stroke reciprocating means for the knife is used toavoiddisengagement of the knives.

The throat plate is cut away in line with the moving knife, so as tomake a pocket C below the working face or surface of the throat plateinto which the fabric may be pushed by the knife as the knife performsthe cutting stroke. This fixed knife is held in 1position by set screwsC.

prefer toslant the bottom of the pocket, as at C, to correspond with theslant of the knife-edge B and also to slant the entrance end C, the exitend C and the side C towards the seam, so that the fabric will contactthe .lint, dust, threads an ends of the pocket curve both horizontallyand vertically and terminate at points on the surface of the plate A Inthe past, cutting devices have been used in which the cutting knifepassed down through the throat plate, and the disadvantage of this wasthat the downward movement of the recipro "iting knife would force thelike down into the mechanism beneath the throat plate until finally itwould happen that the whole mechanism would be packed tight with thismaterial and the machine would not work. The pocket C prevents thisdifliculty because, as shown in Fig. 5, every reciprocating stroke ofthe cutting knife forces a part of the fabric down against the. bottomwall of the pocket, and as the fabric moves forward it wipes out thepocket and takes with it any dust, lint, thread, oil and the like, so asto make the pocket self-cleaning.

It will be evident that while I have shown by my drawings an operativedevice, still many changes might be made in both size, shape andarrangement of parts without departing materially from the spirit of myinto be fed forward the knife is raised and the forward movement of thefabric draws that part of the fabric which was forced down into thepocket by the knives out of the pocket, cleaning it and leaving an uncutsection of the fabric in line with the pocket ready to be out upon thenext stroke. The co-operation of the reciprocating knife and the fixedknife produces a scissors action so as to make a smooth, clean cut; andbecause the knife is behind the needle the cut is made after the seamhas been formed and the seams are made through that part of the fabricwhich has not been disturbed, so that the seams are properly spacedapart. It will be understood that the opposed knife surfaces are ininclined relation to each other, and overlap in such manner as never tobe entirely disengaged. The result is that the knives do not separateand cannot strike or break as they would, if out of line, in the eventof such separation. The lower knife projects above the bed or throatplate of the machine and the upper knife is adapted to penetrate thepocket in said throat plate.

I claim:

1. In a sewing machine, a cutter and a member co-operating with thecutter, said member having a pocket into which the cutter is adapted topress an edge of the severed fabric, the ends of the pocket tapering topoints on the surface of the member.

2. In a sewing machine, a reciprocatory cutter having a beveled edge anda member co-operating with the cutter, said member having a pocket withits ends flaring in the direction of travel of the fabric and its sideopposite the beveled edge. of the cutter substantially parallel withsaid edge.

3. An attachment for a sewing machine comprising a cutter and a memberopposed to the cutter, said opposed member having a closed-bottom pocketinto which the cutter is adapted to press an edge of a cut fabric, saidpocket flaring outward from its closed bottom both laterally andlongitudinally of the direction of travel of the fabric.

4. In a sewing machine, means to sew a seam, a stationary member on oneside of the path of a sewed fabric having a cutting edge adjacent thepath of the seam and a closed-bottom pocket between said cutting edgeand the path of the seam 1, said pocket flaring outward from its closedbottom in the direction of travel of the fabric, and a movable cuttingmember having an edge adapted to cooperate with the stationary cuttingedge and enter said pocket.

5. In a sewing machine, means to sew a seam, a stationary member on oneside of the path of a sewed fabric having a cutting edge adjacent thepath of the seam and a closed-bottom pocket between said cutting edgeand the path of the seam, said pocket flaring outward from its closedbottom to-' ward the path of the seam, and a movable cutting memberhaving an edge adapted to cooperate with the stationary cutting edge andenter said pocket.

6. In a sewing machine, means to sew-a seam, a stationary member on oneside of the path of a sewed fabric having a cutting edge adjacent thepath of the seam and a closed-bottom pocket between said cutting edgeand the path of the seam, and a movable cutting member having an edgeadapted to cooperate with the stationary cutting edge and enter saidpocket, the sides of the pocket being shaped at the ends and side nextthe seam to contact the fabric depressed by the movable cutter.

Signed at Chicago county of Cook and State of Illinois, this 17th dayofApril 1922.

A ELMER M. BATES.

